Method of and apparatus for curling edges on containers



C. BARBIERI Filed Feb. 26, 1940 4 Sheets-Sheet 1 El Y METHOD OF AND APPARATUS FOR CURLING EDGES ON CONTAINES March 31, 1942.

z/E AA7!" Cesare axierj March 31,1942.. l c. BARBIERI 2,278,299

METHOUOF'ANDAPPARATUS FOR CURLING EDGES 0N CONTAINERS Filed Fb. 26,l 1940 4 Sheets-Sheet 2 d' ya Mmh 31, .1942. c. BARBIERI' 2,278,299

' METHOD OE' AND APPARATUS FOR CURLING EDGES ON CONTAINERS Filed Feb. '26, 1940 4 Sheets-Sheet 3 March 31, 1942. C, BAB|ER| I 2,278,299

METHOD OF AND APPARATUS FOR CURLING EDGES ON CONTAINER Filed Feb. 26, 1940 4` Sh6et5shelet 4 Y' IIIIIIIHIZUN' 5 Patented Mar. 31, 1942 METHOD F AND APPARATUS FOR CURLING EDGES 0N CONTAINERS Cesare Barbieri, New York, N. Y., assigner to Dixie-Vortex Company, Chl ration of Delaware cago. IIL. a corpo- Appllcation February 26, 1940, Serial No. 320,733

16 Claims.

This invention relates toimprovements in a method of and apparatus for curling edgeson containers,- the invention being highlyy desirable for curling the edges of containers made of paper or the like, such, for example, as paper drinking cups, ice cream cups, sundae dishes or other dishes, and other paper vessels or containers of the same general character, although the invention may have other uses and purposes as will be apparent to one skilled in the art.

In the past, some diiilculty has been experienced in providing a curled edge in the nature of a downward roll upon containers, and especially so in connection with paper containers of the character of paper drinking cups. This difilculty was experienced mostly with vessels having a relatively wide taper in the sidev walls, for example, a. conical paper drinking cup having an angle in excess of degrees between diam-y etrally opposed elements of the cone. This dimculty was caused mainly by the fact that in providing a curled edge in the nature of a complete downward roll clination of the container wall, so that an unsatisfactory and unsightly product resulted and the roll itself, being loose, did not function properlllylnor did it tend to rigidify the container as a w o e.

- Such difllculty was solved to a material extent by the invention described and claimed in Erik G. Seastrom Patent No. 2;0'17,018, vdated October 8, 1935, and the instant invention embodies structural features not disclosed in the aforesaid Seastrom patent, as will be apparent later herein.

With the foregoing in mind, it is an important object of this invention to provide an improved device for -simply and smoothly curling or rolling the edge of a container to provide a rim bead,v

I giving a-smoother curl to the edge of acontainer wall by virtue of =substantially continuous contact of the curling means with the container when the curl is complete, and with the curl fol- I one or more turns, the roll -would not follow the downward and -inward de- A further object of the present invention is the provision of a contractable curling member which contracts in keeping with the wall slope of a container and at the same time curls the edge of the sloping wall into a rim bead.

Still another object of the invention resides in the provision of apparatus for curling the edges of container walls, especially sloping walls, including a curling iron in the nature of a split ring which, of course, is expansible and contractable.

Another important object of thepresent invention is the provision of apparatus for curling the edge of a sloping or tapering container wall, which apparatus is arranged to permit the curling means to rotate relatively to the container during the curling operation, or the container rotates relatively to the curling means during the curling operation, or permits both the container and curling means to rotate simultaneously, in the same or opposite4 directions, as may be deemed most feasible.

It is also an object of this invention to provide an apparatus for curling the edges of containers having materially sloping or tapering walls, 'which apparatus may be used as an individual and separate unit or incorporated without any substantial change in the curling mechanism in a container making machine to function contemporaneously with the forming of the container.

v-Still a-lfurther-iobject of'this invention is the provision of a new and novel method of curling the edge of a sloping walled container to provide a rim bead.

While some of the more salient features, characteristics and advantages of this invention have lowing closely during formation a sloping containcr wall.

been above pointed out, others will become apparent from the following disclosures, takenin conjunction with the accompanying drawings, in which:

Figure `1 is a fragmentary, part sectional, part elevational view of apparatus embodying principles of the present invention, showing the mechanism in positionl prior to the start of a curlingl elevational view, illustrating a modified form of curling'. mechanism, showing the same in position after the curling operation is completed;

Figure is an enlarged, bottom plan sectional view, taken substantially. as indicated by the staggered section line V-V of Figure 4;

Figure 6 is a fragmentary, part sectional, part elevational view, illustrating another modified form of curling mechanism in position after the completion ofthe curling operation;

Figure 7 is anenlarged', bottomj plan secf usv The present invention has beenvillustrated in several different embodiments to indicate the flexibility lof the invention. Certain of these embodiments vdisclose the invention arranged to permit rotary movement of the curling iron relatively to thel container, while others illustrate a construction permitting rotary movement of the container relatively' to the curling iron, or both. No vitalor substantial change in construction is necessary to have either the container or curling iron rotating while the other is stationary or to have-both rotating at the same time. 1

In the illustrated embodiment of this 'invention seenin Figures 1, 2 and 3, there' is shown an attaching shank I which may be secured to any suitable meansfor imparting'a reciprocable movement t'o the shank, whether those' means be Sparate from or incorporated in a container making machine. Secured to the attaching tapered or sloped complementally to the outerwall I4 of the cam ring.

The spreaders are not permitted any axial stroke relatively to the outer shell 3, but are y only permitted to move radially with respect to this shell by virtue of one or more studs II threaded into the outer shell, each of which has a smooth shank I8 extending into a suitable bore in the spreader, and by virtue of a plate I9 bolted or otherwise secured to the lower end of the shell 3 and extending into a groove in the spreader. With such construction, referring to Figures 1 and 2, it will be seen that the spreader I6 is-slidable relatively to the smooth shank I8 and plate I8.' ,A

A curlingv iron 20 having an arcu'ate annular groove 2| for rolling a container edge is seated in a suitable socket or recess in the respective spreaders I8. The upper portion of the curling iron is provided with a key slot 22, and a key plate 23 bolted or otherwise secured to the lower portion of each spreader is engaged in the slot 22 to hold'the curling iron in position. As seen best in Figure 3, the curling iron 28 is in the nature of a split. ring with a space 24 between the ends of the ring. With reference to Figure 3,

' which illustrates the curling iron at the flnish of and bearing against the collar 8 on the shaft 8,

urges this shaft and likewise the cam ring I3 downwardly relatively tothe shell tending to maintain the spreaders I6 in their outermost Kposition as seen in Figure 1, thus tending to shank, as by belts 2, is an outer shell 3' which is, l

provided at its upper end with a portion 4 of reduced diameter connected through 4apin 5 to.

a main shaft or spindle 6. The pin 5 extends through an elongated slot 1 in the shaft E, which slots limits the stroke of the shaft 6 .and likewise the curling mechanism relatively to the outer shell 3. The shaft 6 is provided with an integral collar 8, which together with a supporting Y,ring 9 fixed tothe shaft and spaced` below theicollar provides 'a seat for a ball-bearing assembly l0.

In the illustrated instance, the ball-bearing assembly performs no real function but is included in the structure so that the mechanism may readily be adapted to permit rotary movement of the curling iron relatively to the-container being operated upon. To so adapt the mechanism, it is simply necessary to disconnect the outer shell 3, which may function as a pulley, from the connecting shank I and shaft 8 somewhat in the manner to be later described in connection with Figure 4.

Above the ball-bearing assembly is a circular supporting plate II spaced from the collar 8, as indicated at I2, and a cam ring I3 having a sloping outer wall I4 is carried by the plate II. The outer portion of this cam ring is provided with a plurality of spaced T-slots, as indicated at I5, each of which accommodates a similarly shaped projecting portion on a curling ring expander or spreader I6. In this instance, three 'maintain the curling 'iron 20 in its fully expanded position.

Beneath the aforesaid bearing support 3 is a thrust plate 26 also attached to the shaft 6. One or more smooth shanked guiding pins 21 depend from thethrust plate 26 and slides freely in suitable bores in a container clamping element 28, the outer wall of which tapers in keeping with the taper of the particular container being worked upon. This clamp 281s supported by a collar 29lon the lower end `:of the shaft 6 and is urged downwardly 'against this collar by a compression spring 30 'bearing against the thrust plate 28 and the clamp. The clamp 28 vided with a central bore 32 to receive the lower portion of the clamp 28 when the parts are compressed. `Normally, the auxiliary clamp 3| depends beneath the clamp 28, as seen in Figure 1, suspended from one or more bolts 33, the head of each of which is slidable in a smooth bore 34 above an annular shoulder 35 in the clamp 28. A compression spring 36 Vis i disposed between the shoulder and the auxiliary clamp to normally urge this clamp downwardly vin spaced relationship to the clamp 28.

The above described structure includes the actuated parts of the curling apparatus. With this structure, it is only necessary to provide a curling plate or container holder 31 for holding a cup or other container 38 in proper position for the edge curling operation. The holder 31, of course,

has an inside taper in keeping with the wall of the container 38, and this holder may be supported by any suitable means embodied in or separate from a container forming machine. It will be noted, especially in Figure 1, that the upper surface of the curling plate or holder 31 is provided with an annular arcuate groove 39 to accommodate a portion vof the' ultimate rolled rim bead on the container, and to guide the first turned-over edge portion of the container during the formation of this rim bead, so that a proper roll is formed.

In operation, the structure above described is exceedingly rapid and accurate. The container is ilrst mounted in the curling ring or holder 31, as indicated in Figure 1, with the upper edge portion 40 of the container projecting above the holder. Then, the shank l together-with the apparatus supported thereby is moved towards the container or, if so desired, the container may be moved towards the shank I. When such relative movement occurs, the auxiliary clampplate 3| nrst engages the inside of the container and as the spring 38 is compressed, the main clamp 23 engagesthe inside of the container. Thus, with the aid ofV the compression spring 30, the container is positively held between the clamps 23 and 3| on the inside and the curling ring or holder 31 on the outside. The upper edge of the container is next engaged by the sloping wall of the curling ring 20, and when the relative movement occurs between the shaft I and the shank I. a distance limited by the slot 1. the curling ring iscontracted by virtue of the spreaders I3 following the slope of the T-slot I in the cam ring I3. The upper edge of the container is therefore caused to follow the arcuatel groove 2I of the curling ring and the contour of the groove 33 in the container holder to form the tightly rolled rim bead 4I seeninFigure 2. Y

It will be especially noted that as the rim bead is rolled, the curling iron both contracts and moves axially with respect to the container, so

thatthe curling iron follows the taper of the container wall exactly to provide a rim bead in tight association with the container wall and of such character as not only to provide a neat drinking rim for the container but also to rigidii'y and strengthen the container as a whole. It will further be noted that by" the simple expedient of merely changing the face angles on the respective parts,a container of substantially any taper may be provided with a rim bead with the present invention. The illustrated container, for example, has an angle of approximately 40 degrees between opposed elements of the container.

In Figure 2, the structure is shown at the finish of the curling operation and, with reference to Figure 3, it will be noted that the curling iron is in substantially complete contact entirely around the rim bead 4I. In other words, there is substantially complete and uniform contact of the curling iron with the container edge all through the curling operation, thereby giving a smoother, more unifomuand more satisfactory rolled edge.

When the curling echanism is withdrawn from the container, the parts tend 'to assume the position seen in Figure l. However, by virtue of the spring 36, the auxiliary clamp plate 3| is last to release its clamping engagement with the container, thereby insuring a positive freeing of the container from the clamp 23 so that the container will remain in its holder 31 and not tend operation need require only a fraction of a second, and the operation may be repeated just as fast as containers may be removed from and inserted in the holder 31.

In Figures 4 and 5, I have illustrated a curling apparatus adapted for use in a container forming machine, a curling operation taking place contemporaneously with the completion of the shaping of a container around a forming mandrel. By way of example, as is the case with all of the other disclosed modiflcations of my invention, I have illustrated the curling of a rim bead on a conical paper drinking cup having a relatively wide taper.

In this instance, there is shown a spindle 42 carrying on one end a container forming mandrel 43. During the curling operation, the spindle andmandrel do not rotate about their common axis, but the mechanism carrying the curling iron may rotate relatively to the spindle and mandrel. Disposed about the spindle above the mandrel is an outer shell in the form of a pulley 44 so mounted as to permit relative axial movement between the spindle and the pulley. The hub of the pulley is recessed to'accommodatea cyclop bearing 45 permitting sliding between the pulley and the spindle. Above the bearing, the pulley carries a flanged collar 46 which may abut a collar 41 iixed to the spindle, thus limiting the axial slope of the pulley and curling apparatus. Below the bearing, the hub of the pulley is provided with a depending sleeve 43, and circumscribing and freely floating on this sleeve is a recessed cam ring 49. The cam ring 49 rests upon the upper part of a ball race 53, and the lower part of the ball race is attached to the end of the mandrel 43. The outer face of the cam ring 49 is tapered, as indicated at 5I, in keeping with the taper of the container wall to be acted UDO!! t In .this instance, a plurality of ring spreaders n ing upon the size of the apparatus, may be used.

Each curling iron spreader is "provided with a pair of spaced arms 53 pivoted as at 54 to one of the spokes 55 of the pulley. The spreaders are thereby suspended from the pivot connectionill. Each spreader is also provided with a hump 56 adjacent its lower end to ride the tapering outside surface of the cam ring 49, and the spreaders are urged into contact with the cam ring at all times by a circumscribing spring 51 seated in a suitable recess in each spreader.

A curling iron 20, of the same character as previously described in connection with Figures 1, 2 and 3, is in this instance carried by the spreaders, a key-supporting element 58 being in engagement with the curling iron and attached to each spreader. A spring 59 disposed between the pulley hub and the bottom of the recess in the cam ring 49 constantly urges the pulley away from the cam ring, thus tending to maintain the curling iron in expanded position. This spring can only act, of course, until the flanged sleeve 46 abuts the limiting collar 41 on the mandrel shaft. In operation, any desired means, not shown in the drawings, may be used both to rotate the pulley 44 and move the pulley towards the mardrel against the vaction of the spring 59. When the pulley rotates, the spreaders 52, cam ring 69, and curling iron 20 will obviously rotate with the pulley. The cup 38 being worked upon is held clamped rigidly in position by the mandrel 43 and a curling plate or cup holder 31 of the 'character previously described. By virtue of the spring 51, the curling iron is contracted as it enters the cup in exact keeping with the taper of the cup wall, so that a rolled rim bead 4I is provided. r

After the formation of the rim bead, the pulley is released, and the spring 59 urges it along the shaft 42 away from the mandrel, causing the spreaders to expand the curling iron to full position for another operation on a new cup. The space between the ends of the curling iron is so small as to cause no interference whatever with the relative rotation between the curling iron and the cup, so that the rim bead is not only smoothly and positively curled downwardly along the sloping wall of the cup, but is additionally circumferentially ironed.

In that embodiment of the invention illustrated in Figures 6, 7 and 8, provision is made for the container-being worked upon to rotate relatively to vthe curling iron. In this embodiment of the invention, a spindle 6D is provided to which the hub of a supporting spider`6l is keyed or otherwise rigidly secured, as indicated at 62. The radially extending legs 63 of the spider 6I are arranged in pairs, with a slot or other opening 64 between the legs of each pair, as seen best in Figure 7. In this instance, four pairsof legs .are shown, although, as explained above, any feasible number may be used, de

pending upon the size of the apparatus.

A plurality of curling iron spreaders 85 are provided, each of which has a bifurcated upper portion 66. This bifurcated portion is disposed within the slot 64 between a pair of spider legs V63-63, as seen best in Figure 8. The spreader; 65 is held in position by a pair of radially aligned links 61, each of which is pivoted at one end,

as at 68, to the spider legs, and is pivotally connected at the other end, as at 69, to the bifurcated portion of a spreader It will therefore be apparent that each spreader may move in an oblique direction which isa combination of vertical and radial movements by swinging on its respective links.

The same character of curling iron, in the nature of a split ring 20, as previously described, is carried by the dspreaders 65, each spreader carrying a key element 10 engaged in the slot 22 of the curling iron. Each curling iron also carries a depending cam rider portion 1| which engages an inside cam face 12 of a cam ring 13 (Figure 6). The cam ring is carried by the spindle 60 but is arranged for slidable movement axially of the spindle. This slidable movement or stroke of the cam ring is limited by the bottom of a recess 14 in the lower portion of aeraaee` ers are in the uppermost position relatively to the cam` surface 12, the curling iron is fully expanded ready to begin an operation upon the upper edge portion vof the container 38.

A cup holding clamp 19 is freely disposed below the cam ring 13 and is held in position by a supporting plate 80 bolted or otherwise secured to the bottom of the cam ring. Between the clamp 19 and the cam ring is a ball race 8| which permits .relative rotation between the clamp and the cam ring.

In this instance, a somewhat differently shaped cup holder or outside cup support 8.2 is provided.

This cup holder has an annular groove in its upper face of the same character as the previously described outside cup holder to aid in the formation of the rolled rim bead. However, the cup holder 82 may be mounted or associated with amechanism for rotating or spinning the cup holder during -the processV of curling the edge of the cup.

In operation, it may be presumed that the spindle, spreaders, curling iron, and cam ring may be non-rotating relatively to the axis of the spindle. It will be appreciated that when the clamo 19 is brought into contact with the inside of the cup 38, the clamp and cam ring will be in the lowermost position with the collar 15 on the spindle contacting the bottom of the recess 14. Consequently, as the axial pressure between the cup andclamp 19 is increased, the cam ring will slide up the spindle to the position shown in Figure 6, which is the completion of the formation of the rim beadv4l. The curling'iron 20 will, of course, follow the taper of the cup wall in the manner previously described during the formation of the rim bead by virtue of the portions 1| of the spreaders 65 riding the cam surface 12, y

During the formation of the rim bead, the cup holder 82 together with the cup may be spinning. When contact is made with the inside of the cup by the clamp 19, this clamp may also spin or rotate with the cup by virtue of the ball race 8l.

very rapidly, as set forth above.

That modification illustrated in Figures 9 and l0 is similar in operation to athe structure. just above described in connection with Figures 6, '1 and 8, in that theexternal cup holder 82, the cup and the inner clamping ring may rotate relatively to the remainder of the structure while the rim bead is being curled or rolled. The main difference between the showing in Figures 6, '1 and l 8 and the showing in Figures 9 and 10 is that the cam ring and a collar 15 on the lower end of the spindle. Above the cam ring 13, a socketed bushing 16 is keyed to the spindle, as indicated at 11, and carries a plurality of sockets for the reception of a series of compression springs 18, each of which has one end embedded in a socket in the bushing 16 and the other end in a similar socket in one of the spreaders 65. These springs constantly urge the spreaders upwardly over the inclined cam surfaces 12 of the cam ring, thereby tending to force the cam ring downwardly along the spindle until the collar 15 engages the bottom of.4 the recess 14 opposite to the position the curling iron spreader elements move only radially in T-slots of the character illustrated in Figures 1, 2 and 3. 'I'he T-slots of Figures 9 and 10 are disposed horizontally, while the T- slots of Figures 1, 2 and 3 are disposed obliquely, but otherwise the structure of the slots and T- tongues riding in the slots is the same.

Referring now to Figures 9 and 10, there is shown a spindle 83 carrying a relatively large flange 84 anda circular supporting plate 85, with a key-slot arrangement 86 on the undersurface of the supporting plate. In this instance, there are-shown four T-slot arrangements equal distances apart, each toaccommodate acurling iron spreader. As stated above, there may be as many curling iron spreaders as deemed feasible consistent with the size of the apparatus.

A curling iron spreader'81, provided with a T- tongue 88 for slidable movement in the aforesaid The rim bead 4I is rolled tightly, inl keeping with the taper of the cup, smoothly and if gbeggparent tha rela slot arrangement 88, is associated with each of theslot arrangements. Each spreader 81 is provided with a depending rider portion 89 for slidable engagement with a cam surface 98 on a cam ring 9| slidably disposed on the spindle 83. The stroke of the cam ring relatively to the spindle 83 is limited by the bottom of a recess 92 in the lower portion of the cam ring and a collar 93 carried on the lower end of the spindle. The spreaders 81 carry the split ring curling iron 28 by means of a key plate 94 bolted or otherwise secured to the spreader, as described in connection with Figures 6, 7 and 8. This ring is of the same character as above described and functions in the same way. Between the lower cylindrical portion 95 of -the cam ring, outside the recess 92, and an inside clamping member 96 is a ball race 91. which permits rotative movement of the.

inside clamp 98 relatively to the cam ring.

A cup holder associated with rotative mechanism engages the outside surface of the cup, as described in connection with Figure 6. The body portion of the spindle 83 is provided with a series of recesses, each to accommodate one end of a compression spring 98, the other end of each compression spring beingf embedded in a recess in its respective spreader 81. These springs constantly urge the spreaders outwardly along the T-slo'ts against the cam surfaces 98 on the cam ring 9|, thereby urging the cam ring downwardly relatively to the spindle until the collar 93 contacts the bottom of the recess 92. At that time, the curling iron is in fully expanded position ready to begin a curling operation.

The operation of the structure shown in Figures 9 and 10 is substantially similar to that of Figures 6, 'I and 8, the clamp 96 first contacting the insideof the cup and pressing the cup between itself and the outside holder 82. With the outside holder 82 rotating, the clamp 96 may rotate along with it by virtue of the ball race 91. As the curling iron enters the cup, forming the rim bead 4I, the cam ring 9| gradually rises on the spindle 83 until it reaches the position seen in Figure 9 at the completion of the curling operation.

The novel method embodied in the present invention is believed to be suiciently apparent from the foregoing description of the several modifications of the apparatus. It will suffice, therefore, to merely add that one of the important steps of the method is the use of a split ring curling iron and the gradual contraction of the curling iron as it enters the cup, such gradual contraction being an oblique movement which is the resultant of a radial and longitudinal movement of the curling iron relatively to the cup, so that the curling iron is caused to follow the taper of the cup Wall. r y From the foregoing, it is apparent A.that I have provided a novel apparatus andalnovelmethod fof curling a rim bead on a paper container or `Qntheiike, the invention being veslaecially' desirable '\f r iseinreonnegilion With alcontainer having a w1de angledianggge walls.y It wili'further m` bead, is provided by wntcffle Curling iren with the edge of the e'dily adaptable folfuse either-within or with- Om cup makmg machine, and it will be noted that th filming von -rnayp'rotate relatively to -tQrup 98mgWmfeiiupon,"r the cup may rotate MAQ thNhrling iron, or both may rotate i MB1-EGON otherwise than is necessitated bythe scope of the appended claims.

I claim as my invention: 1. In apparatus for curling the edge portion of a container, a container holder, a supporting member, means carried by said member for disposition inside a container to clamp the container against said holder, a curling iron in the nature of a split ,ring carried by said member for contacting and rolling the edge portion' of the container upon relative laxial movement between said holder and said member, a cam element. carried by said member, spreader elements also carried by said member and engaged with the curling iron, said spreader elements being positioned to follow said Acam element, and resilient means tending to urge said spreader elements 'to expand said curling iron, said spreader elements following said cam element to contract said curling iron upon relative movement towards each other between the holder and supporting member to form a curled rim bead'on the container.

2. In apparatus of the character described, a container holder in whicha container may seat, a supporting shaft, a main clamping element carried by the shaft for entering the container and clamping it against the holder, an auxiliary clamp carried by and spring-urged away from the main clamping element to insure separation of the container and main clamping element after a curling operation on the edge portion of a container, a cam member on saidshaft, spring means tending to maintain the main clamping element and said cam member separated, an outer shell carried by said shaft, spreader elements carried by said shell and movable radially relatively thereto, spring means urging said cam into engagement with said spreader elements in a manner to hold said elements in outermost position, and a single-piece split-ring curling iron carried by said spreader y elements, said shaft being slidably associated with said main clamping elements and said outer y and move inwardly to contract said curling iron against the action of said spring means when acting on the edge portion of a container.

3. In curling apparatus of the character described, a shaft, a container forming mandrel on said shaft, a container holder engageable around a container on said mandrel, a pulley rotatable and slidable with respect to said shaft, a cam element adjacent the hub of said pulleyv and rotatable relatively to said shaft, a bearing between the cam element and the mandrel to permit relative rotation of the cam element, spring means urging the cam element and pulley hub apart longitudinally of the shaft, spreader elements pivoted to ride the surface of the cam element, means maintaining contact between the spreader elements and cam element, and a split ring curling iron carried by said spreader elements and expansible and contractable as the spreader elements ride the surface of the cam element.

4. In a curling apparatus of the character described, a holder in which a container may be seated, a shaft, an inside container clamp carried by the shaft, a cam member on said shaft, a spider on said shaft, spreaders arranged to ride the cam surface of the cam member, links pivoted both to the spider legs and the spreaders to support and permit radial movement of the spreaders, resilient means urging the spreaders to ride the cam member to outermost position, a split-ring curling iron carried by the spreaders, and bearing means associated with said inside clamp to permit relative rotation between the inside clamp and the shaft and other structure carried thereby, said spreaders being forced to follow said cam member against the action of said resilient means and contract said curling iron during a curling operation on the container.

5. In a curling apparatus of the character described, a holder in which a container may be seated, a shaft, an inside container clamp, a cam member on the shaft, bearing means between the cam member and inside clamp to permit relative rotation therebetween, a supporting member, a plurality of spreader elements carried by the supporting member in a manner to permit only relative radial sliding movement of the spreader elements, means on said spreader elements to ride said cam member, spring means between the spreader elements and shaft urging the spreader elements against the cam member and therealong to outermost position, means to limit the movement of said spreader' elements, and a split-ring curling iron carried by said spreader elements and contractable as said elements ride said cam member against the action of said spring means when the container and curling iron are forcibly brought together.

6. Apparatus for curling the edge portion of a container, including a single-piece split-ring curling iron for engagement with the container and which is variable in size in keeping with variations in size of .the container Wall.

7. Apparatus for curling the edge portion of a container, including a single-piece split-ring curling iron for engagement with the container, and supporting means arranged to carry said curling iron and progressively contract the iron 'during its curling action on the container.

8. Apparatus forcurling the edge portion of a container, including a single piece expansible and contractable curling iron of such size as to establish substantially uniform and complete contact entirely around the edge of the container.

9. Apparatus for curling the edge portion of a container, including a single piece expansible and contractable curling iron of such size as to establish substantially uniform and complete contact entirely around the edge of the container. and mechanism arranged to carry and control the expansion and contraction of the curling during operation.

10. Apparatus for curling the edge portion of a container having a tapering wall, including an integral expansible and contractable curling iron of such size as to establish substantially uniform and complete contact entirely around the edge of the container.

11. Apparatus for curling the edge portion of a container having a taperingwall, including an integral expansible and contractable curling iron for engagement with the edge of the container and relative travel along the container Wall during the curling operation, and supporting means carrying said curling iron and arranged to progressively contract the curling iron in keeping with the taper of the containerwallduring the curling operation. p,

l2. In apparatus for curling the redge portion of-a container, an expansible and contractable curling iron in the ynature of a' single-piece split ring having a groove therein, one wall of the groove being disposed at the same vangle as the container Wall and the remainder being complemental to the desired shape of the resultant curled portion of the container.

13. In apparatus for curling the edge of a container, supporting means, a clamp carried by the supporting means for entering and engaging the inside wall of the container, curling means carried by said supporting means, and bearing means associated with said supporting means to permit relativ'e rotation between the clamp and curling means. f

14. In apparatus for curling the edge portion of a container having a tapering wall, including a holder for a container, supporting means, said holder' and means being arranged for relative axial movement, an expansible and contractable curling iron in the form of a single-piece split ring carried by said supporting means, spreader elements` engaged with said curling iron to control its expansion and contraction, and cam means carried by said supporting means and in engagement with said spreader elements in a manner to cause progressive contraction of the curling iron in keeping with the taper of the container Wall during the curling operation.

15. In combination with-apparatus for curling the edge portion of a container having a tapering wall, an expansible and contractable curling member in the form of an integral split ring.

16. 'Ihe method of curling the edge portion of a container having a tapering wall, including the step of applying pressure substantially uniformly and completely around the edge portion of `the container and of suiiicient degree to curl said edge partida, ,and progressively contracting the area of application in keeping with the taper 0I theoolitainer wall while establishing relative rotgtbnhhdtween the applied pressure and the edle mmf the container.

CESARE BABE 

